Method of removing active sulfur from sulfurized organic compounds



Patented Oct. 13, 1953 METHOD OF REMOVING ACTIVE SULFUR FROM SULFURIZED ORGANIC COM- POUNDS Allan Manteufiel, Union, George R. Cook, Northfield, and William D. Gilson, Crystal Lake, 11]., assignors to The Pure Oil Company, Chicago,

11., a corporation of Ohio No Drawing. Application May 31, 1951,

Serial No. 229,276

6 Claims. (01. 202-46) form. This latter aspect is important particularly when sulfurized materials are used as addizt is employed there are numerous instances in 10 design practice has required the use of special eating composition. These additive agents, which T5 necessary not only to remove the loosely bound other sulfurous corrosive agents that might be present in the reaction mixture. These comagents and various other organic and inorganic corrosive sulfur-containing compounds which are ments have been overshadowed by the manipula- 40 ture are removed by treating the reaction mi:-

furized compounds.

In general in the refining of sulfurized matelight colored end products as well as the pro- 5 concluded by subjecting the semi-refined sulconsolidation of the purification and steam disthe compound or may be present in a more stable 50 tillation steps into one step has apparently been studiously avoided by the prior art investigators because it has been found that unless the teachings of this invention are followed emulsification problems occur which make the refining process and the separation of the refined sulfurized material more difficult. However, these emulsion difficulties may be overcome and a single step purification process carried out wherein both the volatile and the non-volatile unreacted materials and side reaction products are removed from the reaction mixture by a combined purificationsteam distillation refining process by correlating the type of purification reagent employed with the temperature at which steam distillation is conducted.

It is therefore the object of this invention to provide a method for purifying a .sulfurized material without experiencing any difliculty due to the formation of emulsions during the refining process.

A further object is to provide a method for removing unreacted sulfur, loosely bound sulfur and undesirable sulfur-containing side reaction products from sulfurized terpenes.

In accordance with this invention the purifica- 2.

tion of sulfurized organic materials to remove any volatile or non-volatile unreacted materials or side reaction products is effectuated by means of a single step operation in which a dry purification agent is added to the sulfurized mixture, and this resulting mixture is subjected to steam distilling at substantially atmospheric pressure at a sufficiently elevated temperature, not less than about 250 F., to prevent accumulation of moisture within the distillation vessel to such an extent as to cause emulsification difficulties. By limiting the amount of moisture that is permitted to be present, the purification agents and the salts formed during purification never become sufficiently hydrated to allow emulsification to occur. Under the conditions extant during the steam distillation an equilibrium is reached between these salts and the moisture from the steam so that as the purification reaction progresses, a dark viscous solution of a hydrated l mixture of the purification agent and sulfurous impurities collects on the bottom of the distillation vessel. Enough moisture must be present during the purification process so as to allow intimate contactin the purification agent with the sulfurized material through the turbulence provided by the steam distillation yet insufficient to cause emulsification.

This objective is obtained according to the present invention by employing a controlled temperature during the distillation. While the process may be also carried out at subatniospheric or superatmospheric pressures it is necessary to employ an elevated temperature not less than that temperature which would be the equivalent of the 250 F. temperature used in carrying out the process at atmospheric pressure. The upper limit in the distillation temperature is dictated by the temperature at which the sulfurized compound will be decomposed. For example, when treating a sulfurized terpene appreciable decomposition occurs at temperatures above about 350 F. releasing active sulfur which provides a corrosive environment.

It is to be noted at this point that the purification process employed by the present invention is not entirely a neutralization reaction. In contradistinction the greater part of the purification reaction essential to the present invention relies on the interaction between the suliurous impurities and the purification reagent to form organic and inorganic salts which are removed from the sulfurized material by forming a phase which varies in density from the density of the desired sulfurized material. This results in a phase separation which permits the facile recovery of the desired product.

The organic compounds which may be sulfurized and subsequently purified according to this invention are quite numerous. These materials include many types of unsaturated compounds which because of their high reactivity will react with various sulfurizing agents. Specific examples include various types of isoprenoid type materials, either per se or those obtained from such naturally occurring compositions as turpentine and pine oil, various naval stores products such as rosins, hydrocarbons and hydrocarbon mixtures such as petroleum oils, as well as other organic materials which when sulfurized and blended into a mineral oil lubricating composition will impart beneficial properties thereto. The sulfurization reagents which are employed by this invention to form the desired sulfurized product may be either elemental sulfur, the sulfur halides such as sulfur chloride and sulfur monochloride, or the sulfides of phosphorus Such as the sesquiand pentasulfides. Although any conventional method of sulfurization may be carried out to produce the crude sulfurized mixture it is preferred to prepare the sulfurized mixture by controlling the temperatures employed during the sulfurization reaction, This method, which employs elemental sulfur as the sulfur-. ization a ent, is fully described by Smith in United States Patent 2,179,060. Therein is pointed out the advantages of maintaining the reaction at certain specified temperatures in order to obtain the most advantageous results. Specific methods for sulfurizing terpenes are also disclosed by Powers in United States Patent 1,926,648 and Holt in United States Patent 2,443,-

shown by Musselman in United States Patent 2,331,923. Other methods of sulfurization which may be employed to prepare the crude sulfurized material which is refined in accordance with the method described by this invention may also be found in the prior art.

In order that this invention may be more clearly understood the following example is illustrative of the preferred sulfurization method as well as the novel refining process employed in this invention.

Example 1,.-'75 parts of Dipentene #122, which is a commercially available mixture of various terpenoid constituents containing approximately 50% dipentene, 17% paracymene, and 14% paramenthane; as well as other active and inert terpene hydrocarbons obtained from the Hercules Powder Company were charged to the reaction vessel. While stirring, 25 parts of elemental sul fur were added at room temperature or at initial heating temperatures below F. It should be noted that this initial heating temperature is preferred although it is not a critical factor in the instant invention. The reaction temperature was then raised to about 280 F. to 290 F. as quickly as possible at a maximum rate of about 10 F. per minute. The mixture was maintained at this temperature for 45 minutes to 1 hour. Special care was taken when the reaction temperature was between 280 F. and 290 F. A slow dissipation of the heat of reaction eliminated an undeand useful product. It is to this end that this invention relates. After the sulfurization reaction was completed by weight of a combinais preferred that a special reaction vessel with a bottom drain be provided so that as the viscous layer accumulates it can be drawn oiT The results of the refining process described by this invention are seen in the tabulated data included in Table 1. In this table, which shows a terials.

In the following claims the expression organic materials is intended to cover those compounds which will react with a sulfurization agent to Con/Lpcriscn of from terpene base Method of active sulfur removal:

Somples-analyzedaiter treat for active sulfur removal.

1 Added tomixture while steam distilling.

What is claimed is: V

1.. A method for purifying a crude sulfurized organic material which comprises steam distilling the crude sulfurized reaction mixture in the. presence of a combination of non-aqueous alkalis selected from the group consisting. of the alkali metal and. alkaline earth. meta-"l hydroxides and non-aqueous sulfide from the group consisting. of alkali metal and alkal' e. earth metal sulfides at a temperature sufficiently elevated so as. to prevent a greater accumulation of water than is required to produce substantially equilibrium conditions between thev purification refrom the steam but below a temperature at which the desired sulfurized organic materials decompose, the proportions of. said reagents being sufficient to react with the corrosive suliurous constituents of said mixture, carrying out said distillation until the reaction between the said purification reagents and the said corrosive sulfurous constituents of the reac tion mixture is completed and the removal of volatile constituents is efiected, separating the resulting phases, and recovering a non-corrosive,

non-volatile sulfurized mixture.

2. A method of refining. a crude ganic material the crude suliurized reaction presence of a non-aqueous mixture of an alkali metal hydroxide and an alkali metal sulfide at a temperature sufiiciently elevated soas to prevent a greater accumulation of water than is required to produce substantially equilibrium hydration conditions between the purification reagents and the moisture from the steam but below a temperature at which the desired sulfurized organic materials decompose, the proportions oi"- said reagents being sufiicient to remove the corrosive sulfurous. constituents of said mixture, carrying out said distillation until the reaction between the purification reagents and the corrosive sulfurous constituents of the reaction mixture is completed, separating the resulting phases, and recovering a non-corrosive sulfurized material.

3. A method for producing a relatively nonvolatfle, non-corrosive, sulfurized organic material by steam distilling in the presence of a combination of non-aqueous purification reagents consisting of a hydroxide and a sulfide of an alkali metal which comprises initially carrying distillation in the purification reagent selected from the group consisting of hydroxides and sulfides of an alkali metal, separating the resulting phases, recovering a semi-purified sulfurized material, continuing the said distillation in the presence of an added sulfuri-zed orpresence of a methods for active sulfur removal:

Percent. oi total sulfur active toward copper Emulsi at temperature indicated proportion separating the resulting phases and recovering, a non-corrosive,v non-volatile. sulfurized matcrial, said distillations being carried out at a. temperature sufficiently elevated as to prevent a greater accumulation of water than is required to produce substantially equilibrium hydration conditions between the purification reagents and the moisture from the steam but below a temperature at which the desired. sulfurized organic materials decompose.

4, A method for producing. a. relatively non.

volatile, non-corrosive, sulfurized. organic material by steam distilling. in the presence of a combination ot non-aqueous purification reagents consisting of a hydroxide and a sulfide of an alkaline earthv metal which. comprises initially carrying. out. the steam distillation in the pres.- ence of a purification reagent. selected from the group consisting of hydroxides and sulfides of. an alkaline earth. metal; separating the resulting phases, recovering a semi-purified sulfurized material, continuing the said distillation in the presence of an added proportion of the remaining purification reagent. separating the resulting phases and recovering a non-corrosive, non-volatile suliurized material, said distillations being carried out at a temperature sufiiciently elevated as to prevent a greater accumulation of water than is required to produce substantially equilibrium hydration conditions. between the purification reagents and the moisture from the steam but below a temperature at which the desired suliurized organic materials decompose.

5. A method of purifying. a crude sulfurized isoprenoid material which comprises steam distilling the crude suliurized isoprenoid. reaction mixture. in the presence of a combination of nonaqueous purification. reagents consisting of a hy-- droxi'de and a sulfide of an alkali metal at a temperature sufficiently elevated so as toprevent a greater accumulation of water than is required to produce substantially equilibrium hydration conditions between the purification reagents and the moisture from the steam but below a temperature at which the desired, sulfurized organic materials decompose, the proportions of said reagents being sufiicient to remove the corrosive sulfurousconstituents of said mixture, carrying out said distillation until the. reaction between the purification reagents and the corrosive sulfurous constituents of the reaction mixture is completed and the removal of the volatile constituents is. efiected, separating the resulting phases, and recovering anon-corrosive, nonvolatile sulfurized material.

6. A method of refining a sulfurized terpene of the remaining purification reagent,

2,655,469 which comprises steam distilling the crude sulrelatively non-volatile, non-corrosive sulfurized furized terpene reaction mixture at substantialterpene. l atmospheric pressure and at a temperature ALLAN MANTEUFFEL.

GEORGE R. COOK. WILLIAM D.. GILSON.

References Cited in the file of this patent UNITED STATES PATENTS Name Date June 22, 1948 July 27, 1948' purification reagent is completed and the re- 10 Number moval of the volatile constituents is effected, sepa- 2,443,823 rating the resulting phases and recovering a 2,445,983 Watson 

1. A METHOD FOR PURIFYING A CRUDE SULFURIZED ORGANIC MATERIAL WHICH COMPRISES STEAM DISTILLING THE CRUDE SULFURIZED REACTION MIXTURE IN THE PRESENCE OF A COMBINATION OF NON-AQUEOUS ALKALIS SELECTED FROM THE GROUP CONSISTING OF THE ALKALI METAL AND ALKALINE EARTH METAL HYDROXIDES AND NON-AQUEOUS SULFIDE FROM THE GROUP CONSISTING OF ALKALI METAL AND ALKALINE EARTH METAL SULFIDES AT A TEMPERATURE SUFFICIENTLY ELEVATED SO AS TO PREVENT A GREATER ACCUMULATION OF WATER THAN IS REQUIRED TO PRODUCE SUBSTANTIALLY EQUILIBRIUM HYDRATION CONDITIONS BETWEEN THE PURIFICATION REAGENTS AND THE MOISTURE FROM THE STEAM BUT BELOW A TEMPERATUTE AT WHICH THE DESIRED SULFURIZED ORGANIC MATERIALS DECOMPOSE, THE PROPORTIONS OF SAID REAGENTS BEING SUFFICIENT TO REACT WITH THE CORROSIVE SULFUROUS CONSTITUENTS OF SAID MIXTURE, CARRYING OUT SAID DISTILLATION UNTIL THE REACTION BETWEEN THE SAID PURIFICATION REAGENTS AND THE SAID CORROSIVE SULFUROUS CONSTITUENTS OF THE REACTION MIXTURE IS COMPLETED AND THE REMOVAL OF VOLATILE CONSTITUENTS IS EFFECTED, SEPARATING THE RESULTING PHSESE, AND RECOVERING A NON-CORROSIVE. NON-VOLATILE SULFURIZED MIXTURE. 